Fuse indicator



July 19, 1932. F. c. LA MAR 1,868,465

FUSE INDICATOR Filed Nov. 2, 1929 TOR - BY ATTORNEY Patented July 19, 1932 UNITED STATES PATENT OFFICE FRANK C. LA MAR, OF NEW YORK, N. Y., ASSIGNOR T GREAT 'W'ESTERN COM PANY, OF NEW YORK, N. Y., A CORPORATION OF DELAWARE FUSE INDICATOR I This invention relates to electrical fuses, especially to electrical fuses of the cartridge type, and more particularly to an indicator for such fuses which acts to give information as to the integrity of the fusible element.

It is well understood by those skilled in the electrical art, that safety requires all circuits which carry-or are capable of carrying an appreciable amount of current must have inserted safety devices in them to prevent an excessive flow of current under abnormal conditions.

A common safety device is the well known I A principal object of applicants invention is the provision of a means by which the integrity of the fusible elements of a fuse may 80 be ascertained by a visual. inspection without disassembling the fuse or disturbing the position thereof.

Another object of the invention is the provision of a means of the type-specified which $55 may be positioned upon a fuse by a simple manual operation without the use of tools.

A further object of the invention is the provision of a means of the type specified which merely requires two small buttons to be placed on the fuse in order to adapt it to receive the indicating means.

Other objects and advantages will appear as the description of the particular physical embodiment selectedto illustrate the invention progresses and the novel features of the invention will be particularly pointed out in the appended claims;

In describing the invention in detail and the particular physical embodiment select- 59 ed to illustrate the invention, reference will ,be had to the accompanying drawing and Numeral 1 designates the usual hollow cylinder of insulating material as commonly used in cartridge fuses, either of the ferrule or the knife blade type.

On each end of the body 1 ina ferrule type fuse as shown in Fig. 1 are the metallic ferrules 2 and 3 which also would be'present if the fuse were ofthe knife blade type. Outside of and properly attachedto the ferrules are the metallic caps 4 and 5. The structure comprising the parts 1 to 5 inclusive enclose the strip of fusible metal 6 electrically connecting ferrule 2 with ferrule 3.

As the fusible strip 6 is within the opaque case knowledge of its integrity can ordinarily become known only by. removing the structure from the usual clips in which it is placed, .unscrewing a cap, as 4 or 5, and inspecting the contents' I In applicants arrangement an indicator is supplied, which is virtually a fuse of small 4 current carrying capacity as compared with the fuse link 6, which is connected electrically from the metallic ferrule 2 to the metallic ferrule 3 and serves to indicate visually the condition of fuse link 6. because after fuse link 6 is disrupted the auxiliary small fuse wire 7 becomes disrupted and its condition may be observed through the transparent wall 8.

In order to position the auxiliary device applicant prefers to place buttons as 9 and 10 on the ferrules as 2 and 3. These buttons may be attached'in any suitable manner as by riveting or screw "threading but each b utton has the bottom of its head as 11 spaced from a ferrule,as 3, such a distance that a finger as 12 and 13 may be inserted therebetween.

Fingers 12 and 13 are similarly but reversely formed, that is, each has two orifices therein reversely positioned. Finger 13 has a large diameter orifice 14 and a smaller diameter orifice 15. Finger 12 has the large diameter orifice 16 and the smaller diameter orifice 17. I

Fingers 12 and 13 are attached in any suitable manner, as by soldering, to the metallic caps or thimbles 18 and 19 between which is positioned the transparent hollow cylinder, preferably a glass tube 8. The fuse wire 7 of small carrying capacity is attached to each of the thimbles as 18 and 19.

When the complete device is assembled it may be positioned by placing the large diameter orifices 14 and 16 directly over the buttons 9 and 10 respectively. It may then be pushed down into contact with the ferrules as 2 and 3 and then slid lengthwise so as to bring the fingers underneath the buttons 9 and 10 and the smaller diameter orifices 15 and 17 underneath the buttons in which position the indicator will be held in place if the parts are so proportioned that good frictional engagement is secured. To remove the indicator, the motions must take place in the reverse order. 7

Although I have described one particular two metallic buttons one on each ferrule, each button being slightly spaced from the ferrule; two metal fingers, each having'two connecting orifices therein reversely positioned, one orifice of such diameter that the button may pass therethrough, the other of too small diameter for the button to pass therethrough; an electrical indicator provided with terminals connected between the fingers, all so arranged that the fingers may be placed over the buttons and then slid endwise to bring the small diameter orifices under the button.

4. As an indicator for a cartridge type fuse having metallic end ferrules, in combination: two buttons, one on each ferrule, each slightly spaced from the ferrule; an indicator including fingers, one at each end of the indicator detachably engaging the buttons and fastened thereto by both being slid in the same direction endwise.

FRANK o. LAMAR.

physical embodiment of my invention, the

principle, and construction thereof, nevertheless, I desire to have it understood that the particular form selected is illustrative merely and does not exhaust the possible physical embodiments of the idea of means underlying my invention.

What I claim as new and desire to secure 4 by Letters Patent of the United States, is:

1. As an indicator for a cartridge type positioned, one orifice of such diameter that the button may pass 'therethrough, the other of too small diameter for the button to pass therethrough; a transparent hollow body with metallic ends and a fuse wire inside con- 11 cting the ends, one end of the body conected to one finger and the other end to the other fin er, all so arranged that the fingers may be p aced over the buttons and then slid endwise to bring the small diameter orifices under the button.

2. As an indicator for a cartridge type fuse having metallic end ferrules, in combinatlon: two buttons, one on each ferrule,jpach slightly spaced from the ferrules; a small 

